This chapter surveys the economic policies and economic cycles that helped push poor migrant Colombian farmers into coca production, a new crop, over three decades from the 1960s and 1990s. First, it reveals that apart from classic issues of Colombia’s political vulnerability to illegal drugs and violence, a specific political economy was in play. Colombia became ripe for illicit coca because of dynamics of economic inequalities and insecurities created by the country’s coffee economy, and by related elite practices of business illegality and speculative boom investing. The second part of the chapter surveys the impact of this political economy in three core areas where campesino migrants flocked after the mid-1970s: the new Amazonian departments of Guaviare, Putumayo, and Caquetá. These case studies reveal a lack of sustained governmental support in such basic local services as education and security, scarce legal livelihood alternatives, and dynamics of social inequality. By exploring the links from national economic policy and elite practice to the rural economies of the Amazon frontier, this chapter connects the particular political economy of Colombia to the explosive growth of coca.